RACE法克隆甜菜NR基因及生物信息学分析

RACE cloning and bioinformatics analysis of nitrate reductase in Beta vulgaris

关键词:  甜菜  生物信息学  硝酸还原酶  RACE  重力

Key words:  Beta vulgaris  bioinformatics  nitrate reductase(NR)  〖JP3〗rapid amplification of cDNA ends(RACE)  gravity

摘要:

硝酸还原酶是氮素代谢的关键酶和限速酶，研究硝酸还原酶的功能对提高甜菜的产量具有重要作用。运用RACE法克隆出甜菜的硝酸还原酶基因，并利用生物信息学对甜菜NR进行主要结构分析和功能预测，并使其在拟南芥中表达，观察根对向重性应答过程中的弯曲情况。结果表〖JP2〗明，利用RACE法克隆得到甜菜NR cDNA全长为2 760 bp；甜菜NR为易溶、亲水性强的蛋白；二级结构预测结果显示，甜菜NR为混合型蛋白；甜菜NR含有钼辅因子、细胞色素b5、FAD及NADH结合域，具有跨膜区域，但不含有信号肽；利用拟南芥突变体观察到野生型比突变体的弯曲较快，暗示甜菜的NR基因可能通过调节NO积〖JP〗累参与植物向重性应答。

Abstract:

Nitrate reductase is an important and limited enzyme in nitrogen metabolism. The functional research of nitrate reductase plays a key role in increasing sugar beet(Sb) yields. In this study，SbNR gene was cloned by RACE and its 3D structure and physiological function were analysed by bioinformatics and expressed in Arabidopsis thaliana to show the gravity. The results were as follows:the full length of SbNR gene was 2760bp；SbNR was soluble and hydrophobic；secondary structure analyses showed that SbNR belonged to mixed protein；SbNR was a new member of NR family，containing molybdopterin binding，cytochrome binding，FAD binding and NAD binding domain. It had no signal peptide，but one transmembrane domain in C terminal，and the mutants showed later response to the gravity，and which confirmed that NO involved in plant’s gravity.